For at least twenty centuries before the European invasions of the 1500s, artists from the Pre-Columbian cultures of Mesoamerica and the southwestern United States elaborated a wide range of elite objects with mosaic tesserae, including human and animal skulls, scepters, knife handles, diadems, pectoral ornaments, masks, disks, plaques, and jewelry for the ear, nose, and lips. Maya, Mixtec, Aztec, and Ancestral Puebloan artists fashioned the tesserae from a variety of culturally significant materials, including jade, turquoise, iron oxides, and many types of marine shell. Both native accounts and modern research have shown that these materials were selected primarily for their hue, with the blues and greens of turquoise and jade the most highly esteemed. Turquoise in Mexico and North America is an ambitious and comprehensive collection of papers presented at a conference held in conjunction with the exhibition Moctezuma: Aztec Ruler (Colin McEwan and Leonardo López Luján, eds., London: British Museum, 2009). The key issues the volume addresses include materials analysis of objects elaborated with turquoise and other blue-green stone mosaic, scientific methods for determining turquoise sources, manufacturing techniques, trade networks, and the meaning of turquoise in ancient Mesoamerica and in the southwestern United States. Other articles explore the history of Mesoamerican turquoise mosaic objects in European collections from the sixteenth to the nineteenth centuries, modern turquoise mining in Cerrillos, NM, and turquoise in contemporary Native American jewelry.

Jonathan King introduces the volume, beginning with the chemical composition of turquoise, the conditions of its formation, and notes on its use and meaning in Europe and the Middle East prior to 1500. While many turquoise mines produce distinctively colored stones—for example, Sleeping Beauty from Arizona is sky blue—color can vary widely, even in the same deposit. Identifying the materials used not only informs conservation, but also yields data that can often be interpreted employing native hermeneutics. Materials analysis also shows promise in identifying the locations of ancient mines, which are generally thought to be in the southwestern United States, at a great distance from the Mesoamerican cities. Two articles in the opening section deal with nine British Museum objects, with analyses of the composition of their mosaic tesserae, manufacture, and how they were mounted. In the first contribution, Caroline Cartwright, Rebecca Stacey, and Colin McEwan analyze the wood supports of several of the objects, as well as some of the other materials employed in their creation. They begin by noting that the term “turquoise mosaic” is used purely for the sake of convenience, since scientific analysis demonstrates that at least eighteen other kinds of materials were also used in the British Museum objects, such as gold, flint, deer hide, and shell. Although these pieces have been under intensive analysis since 1992, and the results of some of these investigations have been published in Turquoise Mosaics from Mexico (Colin McEwan, Andrew Middleton, Caroline Cartwright, and Rebecca Stacey, London: British Museum, 2006), the present article adds new data. Of the works assembled on wooden supports, six used Cedrela odorata, or Mexican cedar; one is an unidentified species of pine; and the dog head mirror frame is made of E. coralloides, the coral tree, or coralín. The authors speculate that these woods were selected because their resinous properties retarded decay, and also because the relatively low specific gravity of these woods made carving easier (11). Other insights deal with the use of conch, mother of pearl, and spondylus shell inlay on the British Museum objects. The second article by the British Museum team reports on the results of a variety of scientific techniques used to analyze the composition and distribution of turquoise on the objects, and demonstrates that in some cases mineralogical turquoise was the least common material. The knife handle, for example, is primarily elaborated with green malachite, white conch, and red spondylus shell. In contrast, other works, like the double-headed serpent and the so-called “warty” mask, were almost entirely decorated using turquoise of different hues. The authors conclude that while the cultural significance of turquoise is well known to students of ancient Mesoamerica, the other materials deployed on these masks should also be investigated.

Other articles in this section directly address how the turquoise tesserae were manufactured, and the implications of the data for questions of their origin. Adrián Velázquez Castro et al. discuss the excavation and restoration of the turquoise mosaic disk discovered in Offering 99 in the Aztec Templo Mayor in Mexico City. Of the total of approximately fifteen thousand tesserae used in the disk, almost all were mineralogical turquoise, rather than “turquoise substitutes” or “cultural turquoise,” as similar stones like malachite are termed in the literature. The authors argue that the purity of the materials used on the disk can be explained by its patronage and context; only the highest-quality turquoise was used as offerings in the Aztec Empire’s most important temple. But their research raises an issue that shadows most of the studies in this volume. The ancient Mexicans selected stones based on their hue, rather than whether they were mineralogical turquoise. In other words, current scientific definitions of what turquoise is must be carefully compared with native taxonomies. Velázquez and his coauthors also demonstrate that not only were many of the tesserae of the Offering 99 disk reused from earlier objects, but that their manufacture techniques matched those found on other Aztec objects from the Templo Mayor. They were likely made by abrasion against basalt rocks and cut with obsidian blades, characteristics that point to manufacture in the Aztec capital of Tenochtitlan. The Templo Mayor turquoise disk tesserae do not match turquoise objects made either at Chalchihuites in Zacatecas, Mexico, or those recovered from Chaco Canyon, New Mexico. While rhyolite tools were used for abrasion and flint for cutting at Zacatecas, at Chaco Canyon turquoise appears to have been ground on sandstone and cut with obsidian and flint (80–81).

Among the most vexing issues in the study of ancient Mexican turquoise objects has to do with the sources of the minerals, as there are few known turquoise mines within the limits of ancient Mesoamerica. Determining where archaeologically recovered turquoise objects were mined has proven difficult because of the wide variation in the mineral’s composition, even in samples from the same deposit. In the present volume, Sharon Hull and Mostafa Fayek report on a new technique for determining turquoise sources based on stable isotopes of hydrogen and copper, which vary geographically, but not within a single deposit. The authors used a secondary ion mass spectrometer (SIMS) to begin assembling a database of values for known turquoise mines and a second data set based upon archaeologically recovered samples. In the first group, they tested eight mines, from Sleeping Beauty, Arizona, to the Castillian mine in New Mexico, but oddly, not Cerrillos, New Mexico, which is the most famous Pre-Columbian turquoise mine in the southwestern United States. When these values were compared with those derived from objects excavated at Chaco Canyon and the Guadalupe ruin, a Chacoan outlier, many samples could be connected to their original mines. In another article in this volume, Alyson M. Thibodeau et al. propose that turquoise may be sourced using lead and strontium isotopes. These techniques offer much promise for finally answering where the turquoise used in ancient Mesoamerica was mined.

The second half of the volume presents studies of the meaning of turquoise in the contexts of ancient Mesoamerica and the southwestern United States, as well as papers on the history of ancient Mexican turquoise mosaics in European museums. Frances Berdan opens the section with an article that explores the historical prose and pictorial sources for data on how the Aztecs acquired and used turquoise. She notes that the sources give many Nahuatl terms for varieties of turquoise, which they distinguished by color, quality, and shape. Berdan reminds readers that whether all of these stones were mineralogically turquoise matters less than what the Aztec or Mexica thought. They considered these blue and blue-green stones to be precious, sacred, and closely associated with the both deities and the native nobility (92). Berdan notes that turquoise is not naturally found in the Basin of Mexico, and was acquired through trade, tribute, and exchange. Of the thirty-eight tributary provinces in the Aztec Empire, only three paid part of their annual tribute in raw turquoise stones and finished objects: Tochpan on the Gulf Coast, Quiauhteopan in Guerrero, and Yoaltepec in the Mixtec region (97). All three provinces were located on major trade routes, and Berdan speculates that they acquired their tribute from traders who brought the stones from much further afield, even from the southwestern United States.

Two articles in this section address the role of turquoise in native knowledge systems: Karl A. Taube considers turquoise symbolism in Pre-Columbian Mesoamerica, and Peter M. Whiteley examines the stone’s meaning and use in both the Ancestral Puebloan peoples and in contemporary Native American societies of the American Southwest. Taube’s analysis demonstrates that many features of turquoise symbolism among the Late Postclassic period (1250–1521 CE) Aztec can be traced to the Early Postclassic period (900–1250 CE), when the Toltec Empire first began importing large quantities of the stone into Mesoamerica. The Toltecs, based at Tula, Hidalgo, inserted turquoise into a preexisting symbolic complex that included the sun, fire, the souls of warriors, meteors, and centipedes (117). Around 900, turquoise began to supplant jade, previously the most valued gemstone. But whereas jade was associated with water and maize, the Mesoamerican staff of life, turquoise was associated with the sky, fire, heat, and warfare (132). In painting and sculpture at both Tula and at the Maya city of Chichén Itzá, rulers and warriors are shown wearing numerous costume elements decorated with turquoise mosaic, from headdresses and mirror disks worn at the small of the back, to breast ornaments shaped like butterflies. Several of these costume elements were first used at the Classic period (250–900 CE) city of Teotihuacan, and were closely associated there with fire, warfare, and sacrifice. For example, much evidence points to a close association at Teotihuacan of butterflies with fire and the souls of dead warriors. But there was no turquoise at Teotihuacan. The later Toltecs associated turquoise with most of the same concepts, and inserted the mineral into the earlier symbol set. For turquoise in the southwestern United States, Whiteley limns a complex of meanings that represent both continuities as well as significant divergence from those outlined by Taube for Mesoamerica. Whiteley’s discussion is strongly influenced by Claude Lévi-Strauss’s interpretation of Native American culture as fundamentally organized around conceptions of duality, which can be observed in religion, social organization, mythology, and even architecture. There is considerable evidence that dyadic concepts were significant in ancient times, and they still figure prominently among contemporary Pueblo peoples. Turquoise is associated with the sky, water, and fertility. Its dyadic complement in Puebloan culture is the squash and its symbolic complex, including scarlet macaw feathers, Spondylus shell, and other red materials (145). Turquoise also figures in such important symbolic polarities as male and female, summer and winter, day and night, ice and fire, and hard and soft. And in color-directional symbolism turquoise is associated with the southeast.

The last articles in the volume survey the history of Mexican turquoise mosaic objects in European collections, from the Renaissance era to the nineteenth century, when Henry Christy acquired the works still associated with his name in the British Museum. Two further articles focus on turquoise in contemporary southwestern Native American jewelry. The native jewelers Gail Bird and Yazzie Johnson highlight a range of contemporary approaches to materials. In the modern market system, turquoise continues to be imbued with symbolism, even as many artists are combining the mineral with non-traditional materials like gold.

This richly illustrated volume represents a welcome addition to the literature on the meaning and use of turquoise in mosaic work in ancient Mesoamerica as well as among the Pre-Columbian and contemporary native peoples of the American Southwest. The contributions balance modern and Pre-Columbian hermeneutics and taxonomies. The data resulting from scientific materials analysis must be compared to ancient Mesoamerican and Ancestral Puebloan ways of thinking about the meaning of blue-green stones. Turquoise in Mexico and North America also exemplifies a recent trend in Pre-Columbian Mesoamerican studies for detailed materials analysis of shell artifacts, stone sculpture, ceramic vessels, as well as objects of wood and feathers. These researches prove that the stones, as well as their supports, pigments, binders, and adhesives, were carefully selected, not solely for their utility, but also according to a host of criteria that are only now becoming clearer.